Generally, grid services are provided based on grid technologies and Web service technologies. A grid service is predominantly provided for a structure that shares resources distributed in a fixed network based on the grid computing technology, and a service execution environment. Recently, as the standard interface system that gives intelligence to a grid and is provided for various kinds of apparatuses, which are operated under different environments, Web and semantic technologies are being introduced. Further, associated scenarios, application systems, and toolkits are being researched and developed such that the grid can be used as a computing grid, a data grid, or an access grid according to the use cases.
In WSRF (Web Service Resource Framework) and OGSA (Open Grid Service Architecture) that have recently been issued, the grid service is defined as a distributed computing and data processing infrastructure that allows geographically and structurally distributed heterogeneous resources to be efficiently used using a stateful Web service. Further, access techniques that are usable in a mobile environment are being researched and developed.
In a grid system, VOs (Virtual Organizations) include individuals, groups, and institutes that temporarily or dynamically construct an integrated environment to share resources for a common goal. However, the grid systems and applications construct the virtual organizations, which are usable in the fixed network, provide required services, and support the life cycle during the execution. A method that uses mobile resources as the virtual organizations has not been suggested.
The grid service is provided for resources connected to the fixed network, and is in development to be used in a collaborative environment for applications to various fields, such as IT (Information Technology) information processing, NT (Nano Technology), and BT (Bio Technology), under different environments. As a representative example, Globus Alliance has developed application services, such as GRAM (Grid Resource Allocation and Management protocol), MDS (Monitoring and Discovery System), GSI (Grid Service Infrastructure), GASS (Grid Access to Secondary Storage), and GridFTP, base on GT (Globus Toolkit).
Further, for the HPC (High-Performance Computing) community, various kinds of tools and platforms, such as WebCom/WebCom-G, Grid Service Broker, Grid Portal SW, Grid Packaging Toolkit, MPICH-G2, Condor/Condor-G, HPC4U Middleware, Gridway metascheduler R-GMA (Relational Grid Monitoring Architecture), and NWS (Network Weather Service), have been published. As the commercial grid systems, Access Grid, gLite, IceGrid, NorduGrid, Open Science Grid, OurGrid, Sun Grid, and GRIA (Grid Resources for Industrial Applications) are provided. The new release of platforms such as WSRF.NET and the like has also been provided. The standards and APIs used in the grid are stated in WSRF, CORBA, OGSA, OGSi, and Distributed Resource Management Application API. Further, technologies for supporting the Web service have been incorporated so as to develop the technologies, such as Knowledge-Grid, Semantic-Grid, and the like.
At present, the major issue of the grid service is to use the mobile resources as grid resources while accepting wireless and mobile characteristics and requirements. To this end, a case where a user who owns a mobile phone uses the grid service through a public wireless LAN (WLAN) for a specific application, such as e-Health, is being studied.
The mobile grid is highly required for the mobility control. It is logically/functionally seen that a single domain (or network/service provider) can be made in connection with an existing mobile communication infrastructure. However, an architecture that can provide mobility control and location information under various heterogeneous nomadic/mobile communication environments is being studied as a problem to be solved for the development of the technologies.
In another technical field, for example in a nomadic/mobile communication field, 2G/3G cellular, WLAN (Wireless LAN), WiBro/WiMAX (Wireless Broadband/World Interoperability for Microwave Access), telemetics, and a location-based service can be exemplified. At present, various heterogeneous systems and services are mainly provided through separate operator domains. Further, a horizontal hand-off service between operators of the same technical standards is provided according to technical characteristics of wireless transmission and service agreements.
The nomadic/mobile communication systems and services have been developed to 3.5G and 4G systems so as to support a fast wireless transmission technology, an ALL-IP-based network service, a multimedia service environment, and a personal communication service environment. Particularly, in the 4G mobile communication, research and development is being undertaken on the basis of a virtual scenario in which a service is possible such that various wireless and mobile communication systems can be incorporated. Further, the search and development are progressing to accept a pervasive communication environment.
In the 4G mobile communication, a user can receive a service in an operator domain or a service provider domain and, even if he moves to another domain, can select a service communication environment according to his service condition and continuously receive the service while mobility is secured between the domains. This is necessary in a ubiquitous environment in which various nomadic/mobile communication systems, various fixed networks, and broadcasting networks are incorporated.
In view of the service and application of nomadic/mobile communication, the key function is management of mobility and location information. At present, an individual network operator or service provider controls mobility and manages location information. Accordingly, for inter-networking between the domains or service collaboration between different kinds of networks, a vertical hand-off (Vertical HO) is required between the systems or domains using different wireless technologies. To this end, the wireless access layer has a function of supporting the vertical hand-off. Further, in the network and application layer, a problem of sharing of collaboration information between the domains that can secure personal mobility and service mobility in order to maintain a continuous service session should be resolved.
Meanwhile, location information may exist in various forms by mechanisms used in the individual nomadic/mobile communication networks. A personalized application or a custom service application requires information that can dynamically use location information of neighboring resources according to environments of mobile resources. That is, it is necessary to manage information that can be recognized according to a change in context. To this end, additional concentrated management nodes and processes are needed. Particularly, an ability to support session mobility is needed.
In the mobile communication field, a tendency in the application of the grid is still in a conceptual and experimental phase.